Gas produced by the gasification process for integrated gasification power plants and industrial process applications needs to be cooled for effective gas treatment. Typically, the thermal energy of the raw gas is used in the combined cycle unit to improve the performance of the power cycle. Additional low grade heat, typically below about 150.degree. C. (about 300.degree. F.), is also normally available in the raw gas. However, this low grade heat is too low in temperature for steam generation for the bottoming cycle. Additional sources of low grade heat exist and are available in other sections of the integrated gasification unit, such as the air separation unit, the sulfur removal/recovery unit, heat recovery steam generator, and other subsystems. This low grade heat energy is normally rejected to the cooling water, or sometimes used for liquid heating duties, which have minor performance benefits.